This invention relates generally to the field of aquarium filtering apparatuses used to remove undesirable elements from aquarium water to maintain an optimum environment for the inhabiting fish. More particularly, the invention relates to systems where the filtering operation is performed externally to the aquarium tank, and which utilize a gravity, water pressure or siphon system to remove water from the aquarium, such that a suction pump is not required to draw or deliver water from the tank to the filtering mechanisms.
A problem encountered in conventional gravity, pressure or siphon-type filtering systems is that they lack adequate safeguards to prevent outflow of water from the tank in the event that water return is blocked, reduced or otherwise halted, such that the tank may be completely drained if the problem is not detected in time. This will result in the death of the marine life, and the removed water will overflow the filtration reservoir and cause damage to furniture, carpets, etc. A typical way to address this problem, as shown in U.S. Pat. No. 4,684,462 to Augustyniak, is to suspend a small, open-topped, water receptacle near the surface of the water within the aquarium. Water is drawn by the external filtering system directly from this overflow tank rather than from the aquarium itself. In the event that water removal exceeds water return to the aquarium, the water level in the aquarium drops below the top of the overflow tank and no further water can be flow out through the drain conduit. Such water overflow tanks are unsightly and reduce space within the aquarium. Furthermore, the return pumping means of the external filtration system will continue to operate, possible resulting in overheating and failure. An even less effective mechanism is shown in U.S. Pat. No. 4,220,530 to Gabriele, in which a visible indicator is triggered in the event that the filter media becomes clogged.
While some systems incorporate float valves to stop water flow under certain conditions, typically the valve is located upstream of the filters, meaning that the float valve mechanism itself may become inoperational due to contamination or debris. Such a system is shown in U.S. Pat. No. 2,729,337 to Alferman. An additional problem in many conventional systems is that the water return pumps are relatively noisy, as is the cascade box utilized in many systems.
It is an object of this invention, as described in more detailed below, to address and obviate the problems referenced above in connection with gravity, pressure or siphon filtering systems. It is an object of this invention to provide an aquarium filtration apparatus or system that incorporates one or more float valves to stop outflow from the aquarium in the event that return flow to the aquarium is blocked or reduced. It is a further object to position the float valve submerged within filtered water such that damage to the float valve operational mechanism from deleterious effects of the marine environment is reduced. It is a further object to provide at least one filtering means upstream of the float valve such that water passing through the float valve is processed to remove particulate matter and debris. It is a further object to provide the upstream filtering means within a sealed housing or chamber. It is a further object to position the return pump and any internal filtration pumps submerged within filtered water to reduce noise.
The invention comprises a filtering apparatus system for an aquarium or other liquid retaining means, where the water is delivered by gravity, water pressure or siphoning means to the filtering apparatus, such that a powered drain pump is not required to remove water from the aquarium tank. In a basic embodiment, the water from the tank is delivered through one or more float valves into one or more filtering means, such as a cascade box and filter sock, to remove undesirable particulates and other matter from the water. The filtered water is retained in a reservoir sump, and the level of the water in the sump operates the float valve. A pump returns the filtered water to the tank. In the event that the water level in the reservoir rises above a maximum desirable level, which would occur in the event that more water is being removed from the tank than is being returned to the tank due to failure of the return pump, blockage of the return conduit, loss of electrical power, etc., the float valve closes and the automatic withdrawal of water from the aquarium tank is stopped.
In an alternative and more preferred embodiment, the water flowing from the tank is first delivered to an enclosed housing which contains one or more filter socks or other filtering means, such that the water flowing from the aquarium tank is pre-filtered to remove large matter and debris prior to the water passing through the float valve. The water is then passed through other known filtering means and into the filter reservoir sump, from where it is pumped back into the aquarium by a return pump.
In a most preferred alternative embodiment, the float valve, the return pump and any secondary pumps for movement of the water within the filtration apparatus are positioned so as to be immersed below the surface of the water within the filter reservoir sump. In this manner the operational components of the float valve are less susceptible to damage from salt creep, mineral deposits, etc., and the noise of the pump or pumps is muted by the water in the reservoir sump.